So im new to piano and i was wondering if chopins prelude op.28 no.4 would be good to learn in order to understand chords and their progressions better. I heard a man say once that the most important skill in playing the piano is understanding chords. Or at least for improv.

This was one of the first pieces I learnt when I started studying piano a bit more seriously.
For me it was a great school, because it is easy to play, but difficult to master. I suggest you to search the piece played by Brailowsky.
In the score that I studied, there is a "stretto" during the last "forte". You can hear it in the Brailowsky record. It adds much to the execution, IMHO.